I have about 50 playlists sorted by genre and decade. Those are my cheat-sheets, I guess you could call them. But I spend 1-2 hours making custom playlists for EACH AND EVERY event I do. While they are ALWAYS subject to change on the fly, it does give me a solid foundation to build upon. I use my clients 3 lists to build my custom playlists - Must-haves, nice-to-haves and the do-not-plays.